Your doctor may adjust your dose if needed. If you experience chest pain, dizziness, or nausea during sexual activity, call your doctor immediately and avoid sexual activity until your doctor tells you otherwise. The following information includes only the average doses of this medicine. Push the plunger of the syringe, then insert the tip into the bottle while holding the bottle upright on a flat surface. These patients had erectile dysfunction at baseline that was characterized by median categorical scores of 2 a few times on principal IIEF questions.Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in test1.ru is also used to treat pulmonary arterial hypertension, a serious heart and lung test1.ru drug is more popular than comparable drugs. It is available in generic and brand versions. Generic sildenafil is covered by most Medicare and insurance plans, but . In , a meta-analysis of trials determined that while Viagra is the most effective of the various ED drugs on the market, it also has the highest incidence of side effects—headache, upset stomach, vision loss, blue-tinged sight, back pain, muscle pain, nausea, and dizziness, just to name a few common ones. Examples of Viagra’s more commonly reported side effects include: headache. flushing (temporary warmth, redness, or deepening of skin color) stuffy nose. indigestion (upset stomach) mild vision.